1. Field of the Invention
The classification of art as established by the U.S. Patent and Trademark Office is believed to place this invention in the general Class entitled, "Ships" (Class 114) and in the subclass entitled, "miscellaneous" (subclass 0.5) and the subclass entitled, "hoisting" (subclass 51).
2. Description of the Prior Art
Barges and those equipped with cranes are well known and are shown in several U.S. patents. Barges with hydraulically or otherwise actuated rams with pad ends adapted to extend out to the floor of the shallow water in which the barge is to be used are also known. In general, barges and cranes mounted on barges include barges in which the crane is mounted upon the top deck for transportation and use. It is believed novel to provide safe storage of the crane without damage from the elements or salt air during non-use or transporting. In the present invention there is provided a barge which may be powered or may be a towed unit. This barge has mounted on each of its four corners a hydraulically actuated ram upon whose end is mounted a foot or platform which is adapted to engage the bottom of the river or harbor in which the barge or crane is to be used. These hydraulic rams and the foot portions thereon are moved selectively downwardly to cause the barge to be lifted to a position above high tide buoyancy so that the barge is lifted and not affected by tides or waves and is a stable platform above nominal high water activity. With the barge thus placed or positioned, a hatchway cover is removed allowing the crane to be brought upwardly by means of hydraulic screws or the like. Four screws are depicted as bringing the crane into a condition above the deck of the barge so that it can be normally operated in a 360.degree. rotation. The platform which carries the crane has four or six levers or beams attached thereto which are swung and attached to the outside walls of the barge so that this platform is brought into carrying engagement with the shelf portion provided on the outer walls. All of the load of the crane is transmitted to the walls of the barge and to the pad portions of the rams at the four corners of the barge rather than to the bottom of the barge. An inert gas is fed into the hold of the barge to protect the crane as it is stored below the hatch. A secured hatch cover is provided to cover openings into the barge and they are equipped with gaskets so that the hold is gas-tight and may be flooded with inert gas.